1999 Ford Ranger Knocking sound

Is the engine oil clean and full? Have you had the computer scanned to see what code is stored?

Engine oil is at where it should be. I haven't had it scanned. My transmission has been slipping here and there and occasionally takes a while to get it to engage after it has been parked.

I would suggest having it scanned to determine what possible areas you are dealing with. It would be helpful.

Thanks, can you recommend a good scanner?

Scanners can be expensive. I always recommend actron scanners because they are priced right and work good. Keep in mind, some can only read engine codes and nothing else.

Thanks. I scanned my truck and it brought up a few misfire codes, which I believe are probably old, yet another issues. If I rev the engine, everything sounds ok, but when I actually drive it makes the knocking.

Here were the codes:

P0300
P0301
P0303

Any ideas?

301 and 303 are specific misfires to cylinders 1 and 3. Do me a favor. Remove those spark plugs and check their condition. Also, it may be a good idea to do a compression test when you have the plugs out.

I'll give those a look, but it seems to be something outside of the engine that is broken. If I rev the engine in park, there isn't an issue, but in gear it knocks like crazy. Last time I drove it, I got it home, but it knocked like crazy at even 10 mph. Sounded like something was clunking under the cab.

Is the change in the knock speed related to engine RPM's or vehicle speed?

It seems correlated with speed.

If it is speed related, then check U-Joints, wheels, axle bearing...

Thanks, I'll put the rear end up on stands and see if I can figure out where the sound is coming from

I have the exact same problem it seems like. It doesn't knock until it gets warmer up and then it knocks badly and gets faster if I speed up but if I stop you can hear it knock, but if I put in neutral it stops and sounds fine but the moment I put in drive it starts knocking again.

Hi,

I have a few questions regarding your post. However, I have to ask if you could repost it in a new thread. We are trying to keep the threads specific to one topic.

Just go to this link, put the details in for your vehicle, and then copy and paste your question.

https://www.2carpros.com/questions/new

I hope you understand.

Take care,
Joe